package com.hmdp.utils;


import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @author Ccoo
 * 2023/12/7
 */
public class SimpleRedisLock implements ILock{

	private String name;
	private StringRedisTemplate stringRedisTemplate;
	public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
		this.name = name;
		this.stringRedisTemplate = stringRedisTemplate;
	}
	private static final String KEY_PREFIX = "lock:";
	private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";
	private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
	static {
		UNLOCK_SCRIPT = new DefaultRedisScript<>();
		UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
		UNLOCK_SCRIPT.setResultType(Long.class);
	}
	@Override
	public boolean tryLock(long timeoutSec) {
		// 获取线程标识
		String threadId = ID_PREFIX + Thread.currentThread().getId();
		// 获取锁
		Boolean success = stringRedisTemplate.opsForValue()
				.setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);
		return Boolean.TRUE.equals(success); // 防止拆箱时出现空指针
	}

	@Override
	public void unlock() {
		// 调用lua脚本
		stringRedisTemplate.execute(
				UNLOCK_SCRIPT,
				Collections.singletonList(KEY_PREFIX + name),
				ID_PREFIX + Thread.currentThread().getId());

	}

//	@Override
//	public void unlock() {
//		// 获取线程标识
//		String threadId = ID_PREFIX + Thread.currentThread().getId();
//		// 获取锁中的标识
//		String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//		if(!threadId.equals(id)) {
//			// 释放锁
//			stringRedisTemplate.delete(KEY_PREFIX + name);
//		}
//	}
}
